“Heavy” hydrocarbon feed streams, particularly petroleum residua, tar sand bitumen, shale oil, etc., generally contain undesirable contaminants such as sulfur, nitrogen, metals and organo-metallic compounds. A hydroconversion process such as hydrotreatment to remove the undesirable components from hydrocarbon feed streams is a known method of catalytically treating heavy hydrocarbon feed to increase their commercial value. Another hydroconversion process is the Fischer-Tropsch (FT) process for preparing liquid hydrocarbons from fossil fuels, especially coal, by conversion to synthesis gas, followed by conversion to liquid hydrocarbons over a FT catalyst.
A catalytic reactor system that has been successfully used to convert coal or heavy hydrocarbon feedstock to lighter products is the ebullating bed reactor. An exemplary ebullating bed reactor is employed in the H-Coal process as described in U.S. Pat. No. 4,400,263; the H-Oil process for the hydrotreating of residuum as described in U.S. Pat. No. 4,526,676; the LC-Fining process also for the hydrotreating of residuum as described in U.S. Pat. No. 4,886,644 . Another exemplary ebullating bed reactor system for the upgrade of heavy oil feedstock employing colloidal or molecular catalyst is described in U.S. Pat. No. 7,449,103 . Other types of reactor system for use in hydroconversion include an internal circulating slurry reactor or a liquid recirculating reactor as described in U.S. Patent Publication Nos. 2007/0140927A1 and 2009/0134064A1 , and a fluidized bed reactor as described in U.S. Pat. No. 4,220,518.
In some reactor systems indicated above, a grid plate (or distributor tray) divides the bottom section of the reactors into two zones. In operation, catalyst and coke agglomerations on the grid plate can cause large variations in reactor wall temperatures requiring shut-downs and reduce the duration of runs. Improved uniform distribution of gas and liquid flow through the grid plate is an important factor in optimizing reactor performance, minimizing the build-up of coke and catalyst on the grid plate and extending process run durations. There is a need for a reactor system with improved distribution design for uniform distribution of gas and liquid flow.